unelss there is a difference ni driver design or the yellow foam is made of a different material than teh black foam (and still unlikely much suond change if it is), then i dont think the difference in colors will make a technical difference in sound.

also most any portable can drive a high efficince 32ohms headphones and the px100 doesnt improves too much from amping as far as i know.

i do enjoy the px100 more than the mx500, and its more comfortable and doesnt fall off. although if i have a mx500, and i could only get 1 more headphone, i would rather get something a bit better than the px100 though, perhap portapro, heh.

but there are people who think music sound good because the gears look attractive in metrosexual ways, than a normal conventional style.

Want to order Sennheiser PX100 Retro.....
A while ago, I upgraded my mx500s to radiosack foam, and they sound better. I'm wonder ...Will the yellow foams improve the sound performance?

I experienced the same phenomenon with the MX500; however, I do not believe that you will hear a difference with the PX100s. The pads that come standard with the PX100s have a thickness and material character similar to that of the yellow foam. This is not the case with the MX500 standard foam and radioshack foam; there is a noticeable increased thickness with the llatter.

Quote:

Originally Posted by Connie

Also, the impedance of these phones are 32 ohms. Do I need to get a headphone amp?

Took 100 hours burn-in and another 100 hours of use (low to normal listening volumes) with me. Still they didn't change dramaticly.
PX100s are good headphones for what they are and certainly better than what you usually get for this size headphones but don't expect miracles.